方法一：

function confirmEnding(str, target) {
// "Never give up and good luck will find you."
// -- Falcor
 str = str.substr(str.length - target.length);
  if(str == target){
    return true;
  }else{
    return false;
  }
}
confirmEnding("Bastian", "n");

方法二：

function confirmEnding(str, target) {
  // "Never give up and good luck will find you."
  // -- Falcor
  if(target.length > str.length){
    return false;
  } else{
    if(str == target || str.substr(str.length- target.length) == target){
      return true;
    }else{
      return false;
    }
  }
}


confirmEnding("Bastian", "n");